jdbc小demo

package top.enjoy.test.jdbc;


import java.sql.*;
import java.util.List;


public class Demo1 {
    
    
    public static void main(String[] args) throws Exception {
    
    

        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        try {
    
    
            //加载数据库驱动
            Class.forName("com.mysql.cj.jdbc.Driver");

            //通过驱动管理获取数据库连接
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo?characterEncoding=utf-8","root","root");

            //定义sql
            String sql="select * from stu";

            //建立Statement对象
            PreparedStatement preparedStatement1 = connection.prepareStatement(sql);

            //向数据库打出sql执行查询 ，查询出结果集
            resultSet = preparedStatement1.executeQuery();

            //遍历查询结果
            while (resultSet.next()){
    
    
                System.out.printf("id："+resultSet.getString("id")+" 姓名："+resultSet.getString("name")+" 年龄："+resultSet.getString("age"));

            }
        }catch (ClassNotFoundException e){
    
    
            e.printStackTrace();
        }finally {
    
    
            //释放资源
            if (resultSet != null){
    
    
                try {
    
    
                    resultSet.close();
                }catch (Exception e){
    
    
                    e.printStackTrace();
                }
            }
            ///------------------------
            if (preparedStatement != null){
    
    
                try {
    
    
                    preparedStatement.close();
                }catch (Exception e){
    
    
                    e.printStackTrace();
                }
            }
            ///-------------------------
            if (connection != null){
    
    
                try {
    
    
                    connection.close();
                }catch (SQLException e){
    
    
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }


        }


    }
}

后面别忘了引jar包

mysql-connector-java-8.0.15.jar